WINDING WINDOW REGULATORS EVERYTHING YOU NEED TO KNOW
The ups and downs of classic lift and drop glass
‘With all wind-down window types, lubrication of the operating gear and channels is essential and oftoverlooked’
For the first quarter of a century of the motor car, if any side protection from the elements was offered at all, it was often in the form of the sliding window arrangement. This allowed beefy arms to not only steer heavy steeds in confined spaces, but to make frantic hand signals too, and was a huge leap forward from the days of cockpits that were totally open to the elements.
However, sliding windows required fiddly catches to keep them from sliding open on braking and, often, annoying rattles gradually worked their way in to the conscious awareness of the car’s occupants, not to mention whistling draughts whisking about whiskers.
Friction drop windows appeared for a while, of the type that may still be seen in use on the carriages of InterCity 125 rolling stock, but a more positive drop-type solution was needed, and this came in the form of the wind-up/down window.
These arrived in smaller cars from the 1930s onwards and were operated via a number of mechanisms. Perhaps the cheapest and most ubiquitous of the operating gear was the pinion-and-quadrant. Initially reasonably high quality components were used, including bronze pinions and cast quadrants, but the need to reduce cost was paramount, for commercially competitive reasons and so pressed steel and drop-forged components quickly became the norm.
Achieving smooth operation wasn’t always easy and so rack-and-pinion was a positive, albeit more expensive solution to the problem. The drop glass was attached to the rack at either side, effectively each end of the curled around flexible rack, ensuring even lifting and lowering, with slightly less strain on the components than the quadrant type. In an effort to keep wind-down windows from lowering unevenly, some manufacturers opted for steel cable operation. This provided a relatively lightweight and simple form of operation, but it was fiddly to set up, especially when reinstalling the mechanism.
The three above-mentioned methods of operation all lent themselves to motorised operation, when this became desirable, first in luxurious, high-end motor cars and now in virtually every vehicle in manufacture.
Of these common types, the most difficult to service with regard to classic cars was the cheaper, pressed steel item. Often, the relatively soft steel teeth on either the pinion or quadrant wore away to the point that the winder slipped when operated.
Some of the more common applications remain in production and so sometimes a spot of cannibalisation of new units to repair unavailable older types is possible.
With all wind-down window types, lubrication of the operating gear and channels is essential and oft-overlooked, but certainly helps to keep the system working as designed.
Drop glass rubber seals also need to be in good order to prevent water and dirt ingress, both of which cause early failure of the mechanism.